import 'package:flutter/material.dart';

void main() {
  runApp(
    MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        appBar: AppBar(
          title: const Text("你好flutter"),
        ),
        body: const MyApp(),
      ),
    ),
  );
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});
  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        AspectRatio(
          aspectRatio: 1,
          child: Container(
            color: Colors.lightBlue,
          ),
        )
      ],
    );
  }
}
